AIGLE, Switzerland: Tour de France winner Alberto Contador will be formally investigated for doping. The International Cycling Union said Monday it asked the Spanish cycling federation to open a case against the 27-year-old rider who tested positive for the banned anabolic agent clenbuterol during his third Tour victory this year. The decision comes after six weeks of deliberation between the UCI and the World Anti-Doping Agency since cycling's governing body provisionally suspended the Spaniard. “At the end of a long and meticulous enquiry entrusted to highly qualified, WADA-accredited experts, and considering all the information currently in its possession, the UCI has concluded that disciplinary proceedings should be opened against Alberto Contador,” the UCI said in a statement. Though the governing body tested riders at the Tour, national authorities have responsibility to prosecute doping cases. If found guilty, Contador would be stripped of the Tour victory and likely banned for two years. “Until the end of the proceedings and despite his provisional suspension, Alberto Contador still benefits from a presumption of innocence,” the UCI said. “For additional safety, considering the very low concentration (of clenbuterol) detected, the UCI continued scientific investigations in collaboration with WADA,” it said. “In particular, it conducted a series of new analyses on all the blood and urine samples taken from the rider in the period in question.” The UCI suspended Contador in September after his urine sample taken July 21 contained “very small” traces of the banned substance. It then asked WADA for “scientific support” before proceeding. Contador denies doping and says the clenbuterol came from contaminated meat. Saxo Bank team manager and former top cyclist Bjarne Riis, meanwhile, says Contador will be cleared of any doping suspicion. Riis, who has hired the three-time Tour de France champion for next season, came to the defense of a rider who has been provisionally suspended. Riis says he believes that Contador “is a clean rider” and that he trusted Contador's explanation that the drug came from a steak.